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Decodon verticillatus

Decodon

Decodon verticillatus

swamp loosestrife [Blooms: Jul-Aug]

Showy tick-trefoil flowers are about a 1/2" tall and 1" long, pea-like with five petals — an upper petal (banner or standard) with two elongate, yellowish-cream spots at its base, two lower petals (wings) forming a chamber perpendicular to the upper petal, and another pair of petals forming a "keel" within the wings. Emerging from between the wings and keel is a stout, upward-curved, white tube that bears a single style and several stamens at its tip.

Desmodium

Desmodium canadense

showy tick-trefoil [Blooms: Jun-Jul]

Wild teasel produces one or more flowering stalks 2.5-6' tall, reddish- or pale green, with longitudinal ridges and scattered white prickles. The flowerhead is up to 4" tall and 1.5" across, initially egg-shaped but elongating as it matures. At the base of the flowerhead are narrow, prickly, sharply-pointed bracts up to 6" long that arch up to surround the flowerhead. Individual flowers are packed around the flowerhead like cells in a honeycomb, each flower with a 3/4" long bract that tapers to a sharp point. Individual flowers are white along most of their length, tubular, about 1/2" long, flaring out to four pale purple or lavender lobes; four stamens with white filaments and purple to lavender anthers and a single white style all protrude well beyond the end of the tube. Flowers bloom initially about halfway up the flowerhead but, later, rings of blooms develop at the base and apex of the flowerhead. Cut-leaved teasel was introduced to North America in the 18th century; the spiky flowerheads were used to comb wool and to raise the nap of (aka, "full") fabric. (Thus the species name, fullonum.) I've only seen this plant once in Jackson Park, but hope it returns (but not in excessive numbers).

Dipsacus

Dipsacus fullonum

wild teasel [Blooms: Jul-?]

Pale purple coneflower flowerheads sit alone at the top of the stem; there are 12-20 white to pinkish-purple, slender ray florets, with 2-3 notched teeth at the tips; the ray florets initially splay laterally but droop on maturity. The central disc is domed and covered with disc florets with reddish-purple tips.

Echinacea

Echinacea pallida

pale purple coneflower [Blooms: Jun-Jul]

Purple coneflower flowerheads are solitary, 2.5-4" across, on the end of light green stems with purple streaks. The center of flowerhead is a flattened or (usually) peaked cone of numerous reddish-orange disc florets about 1/4" long, tubular, deep red to purplish-brown in color; stamens bear yellow pollen. The 10-20 ray florets are each 1.5-3" long and 1/4-3/4" wide, initially spreading, but droop as they mature; they are pink to purple, elongate-oval, often with three notches at the tips of the petals.

Echinacea

Echinacea purpurea

purple coneflower [Blooms: Jul-Aug]

Philadelphia fleabane stems are usually unbranched except at the inflorescence, a panicle. Flowerheads are 1/2-3/4" across with 150-300 thin white ray florets, often pink or violet tipped, and densely packed around the 1/2" wide disc; the disc florets are yellow, tubular, and 5-10 mm long. The base of the flowerhead is coved by 1-3 series of light green, appressed phyllaries.

Erigeron

Erigeron philadelphicus

Philadelphia fleabane [Blooms: May-Sep]

Storksbill flowers occur in clusters of 4-8. Each flower is 1/2" across with five hairy, green, widely-spreading sepals; five purplish or pink petals; five fertile stamens with reddish-orange anthers; and five fused pistils, separate at the tips of the styles where five purple stigmas in a star-shape are prominant. The fruit is a long, narrow awl-shaped "storksbill" up to 1.5" long whose base is the mature seeds (usually five) and whose long "bill" consists of the laterally joined awns (long bristle-like structures) of the seeds. The seeds are explosively dispersed when the "storksbill" splits longitudinally into five separate awns; the attached seeds are flung away from each other (at 4 meters/sec). The attached awns also allow each seed to self-bury. Storksbill is native to the Mediterranean; it was introduced to North America in the 18th century and is now naturalized.

Erodium

Erodium cicutarium

storksbill [Blooms: Apr-Jun]

Spotted Joe-Pye weed flowerheads are pink to pinkish-purple, about 8 mm long, consisting of 8-20 disk florets, each with a tubular corolla with five tiny spreading lobes at its apex, five stamens with white anthers, and two long, thin white styles that extend well outside the floret; there are no ray florets. The flowers make either a rather flat or domed cluster (panicle) at the apex of the plant. The bracts (phyllaries) around the base of the flower are purple-tinged or the same color as the disc florets. Spotted Joe Pye weed (E. maculatum) has purple or purple-spotted, hairy stems and flowers with 8-20 disc florets; sweet Joe Pye weed (E. purpureum) has green, hairless stems with purple color only at the leaf nodes and flowers with 4-7 disc florets.

Eutrochium

Eutrochium maculatum

spotted Joe-Pye weed [Blooms: Jun-Sep]

Wild geranium flowers are about 1.5 " across; they have five spindle-shaped, green sepals with a short red-tipped awn at their tips and five purplish-pink petals, twice the length of the sepals, that are egg-shaped with broady rounded tips and have darker fine radiating lines that function as necter guides. The ten stamens have pale yellow anthers; the single pistel has five carpels that splay at the tip of the pistil into a starfish shape. The anthers produce pollen while the five styles' stigmas remain pressed together; after the anthers are spent, the stigmas separate. The fruit is a candle-shaped, cylindrical structure with a sharp tip. The carpels build up tension as they dry until they spontaneously snap near their base (above the sepals); as the carpel violently curls upward, it flings a single seed considerable distances like a tiny catapult.

Geranium

Geranium maculatum

wild geranium [Blooms: Apr-Jun]

Ground ivy flowers are 1/2" long and arise from the leaf axils; they are purplish, trumpet shaped, with a notched upper and lower (the largest) lobe and two small side lobes; the "throat" of the lower lobe is hairy. There are four stamens (two long, two short) with purple to blue anthers, and a single pistil with a bifurcated purple style. The corolla of the flowers is cupped by a hairy, green, tubular calyx that has 15 ridges distributed around the calyx running longitudinally, and five triangular teeth at the apex of the calyx. The fruit is a nutlet that nestles in the calyx.

Glechoma

Glechoma hederacea

ground ivy [Blooms: Apr-May]

Dame's rocket flowers occur in clusters (racemes) of up to 30. Each flower is 3/4-1" across and long, with a long, narrow, tubular, pinkish-green calyx composed of four long narrow sepals. The calyx opens through a narrow throat into four rounded, pinkish-purple (sometimes white) petals; the six pale yellow stamens and the multiple styles poke to various degrees out of the throat. Stems, leaves, pedicles, and the flower calyxes are all downy or hairy. The fruits are long (up to 4"), narrow, ascending, downy cylinders (siliques, typical of mustards) filled with flattened, oblong seeds. The flowers are very phlox-like, but phlox flowers have five petals, and dame's rocket only has four; phlox leaves are opposite on the stem (not alternate) and are narrower.

Hesperis

Hesperis matronalis

dame's rocket [Blooms: Apr-May]

Swamp rose-mallow is a wild hibiscus that prefers wet habitats; the stem can get up to 7' tall. Flowers arise from leaf axils and are trumpet-shaped, 4-6" across with five pink or white petals (sometimes with a reddish-purple throat); and, in the center of the flower, a stout cream colored column that bears both whorls of white stamens with yellow anthers and a white style divided into five upcurving parts, each with a pin-head shaped stigma. Behind the corolla are five light green sepals and 12 awl-like 1" long bracts that curve forwards. This is the more variable of the two local rose mallows; it has white or pink flowers which may or may not have a reddish-purple throat (all are now considered the same species).

Hibiscus

Hibiscus moscheutos

swamp rose-mallow [Blooms: Jul-Aug]

Virginia waterleaf stems are variable in color (green, reddish-green, or reddish-brown) and up to 2' tall. Each upper stem has at their tips one or two clusters (cymes) of 8-20 flowers that is 1-2" in diameter on a 4" stalk (peduncle); the central flower opens first. Individual flowers are 1/4-1/2" long, roughly bell-shaped, white, pink, or light violet in color. Flowers have a green, hairy calyx with five long, narrow teeth fringed with widely-spaced, stout hairs; a tubular corolla with five equal lobes at the open end; five stamens covered with long hairs along their lower half, with anthers initially yellow that later turn dark brown; and a single lavender style with a white, bifurcated tip. Both the stamens and the style are 30-50% longer than the corolla lobes and extend well beyond their edges.

Hydrophyllum

Hydrophyllum virginianum

Virginia waterleaf [Blooms: May]

Common morning glory is a vine up to 10' long with alternate, heart-shaped (never lobed), smooth-margined, almost as wide as long. The stem is green or reddish-purple, covered with long hairs; it twines around adjacent vegetation and objects. Cymes of 1-5 flowers arise from some leaf axils; they sit at the tip of about 4" long pedicels. The flowers are 2-3.5" wide, funnel-shaped, usually deep purple or pink, less commonly blue or white, a single style with a three-lobed stigma, and five stamens. Sepals are relatively short, hairy, and triangular unlike ivy-leaved morning glory (I. hederacea), where the sepals are long and narrow. Other morning glories (Ipomoea sp.) usually have lobed leaves; the superficially-similar bindweeds usually have arrowhead-shaped leaves, not heart-shaped. Common morning glory has sepals that are short and triangular, unlike ivy-leaved morning glory where the sepals are relatively very long and narrow. Common morning glory is native to Mexico; it was introduced to England by 1621, then introduced from England to North America around 1700 as an ornamental (Fang et al., 2013), where it rapidly escaped cultivation.

Ipomoea

Ipomoea purpurea

common morning-glory [Blooms: Aug-Sep]

Henbit's vertically-oriented flowers occur in clusters of 4-10 at the top of stems. They are tubular, 1/2-3/4" long, initially narrow at the short, five-lobed green calyx, but broadening into a hood-like upper lip that is densely covered with short hairs and a drooping lower lip that broadens into two lobes. The stamens are attached to the base of the lower lip but have long filaments so that the purplish anthers are positioned just under the upper lip; the style is white, about 3/4" long, with a two-lobed stigma. The outer surfaces of the flower are purplish-pink to pink; the inner surfaces are white with purplish dots. The fruit is a cluster of four nutlets, each containing a single seed.

Lamium

Lamium amplexicaule

henbit [Blooms: Apr-May]

Purple dead-nettle's whorls of flowers occur in the leaf axils and at the tip of the stem. Flowers are about 1/2" long with a short, five-lobed green calyx and a tubular, purplish pink to white corolla with an upper and lower lip; the lower lip is divided into two lobes, often white with purple spots. There are four short stamens with brown anthers positioned beneath the upper lip and a single style with a two-lobed stigma. The closely-related henbit (Lamium amplexicaule) has much longer tubular flowers and leaves that are sessile or clasp the stem rather than being borne on petioles. The "dead-nettle" name comes from a resemblance of the leaves to some nettles, but the lack of stinging hairs (thus, a dead nettle).

Lamium

Lamium purpureum

purple dead-nettle [Blooms: Apr-?]

Motherwort is a naturalized exotic from Eurasia with stems up to 5' tall (more commonly 3-4'); branches occur near apex, if they are present at all. The flowers are sessile; they occur in whorls just above a pair of opposite leaves in the upper half of the plant, almost completely covering the stem. Individual flowers are about 3/8" long, two-lipped and VERY hairy on the outer surfaces with profuse long, white hairs; the upper lip is reflected backwards and unlobed, while the lower lip is divided into three lobes. The lips are white or light pink with purple spots on the lower lip and purple mottling on the upper lip. Four stamens with purple anthers protrude about half way up the upper lip; there s a single style with a two-lobed stigma that is located between the two longest stamens. The stubby, tubular calyx has five very sharp lobes/spines lending a touch of danger to the flowers; after fertilization, the calyx holds four nutlets, each containing a single seed. Motherwort was introduced from Europe (where it was previously introduced from Asia) primarily as a medicinal herb; it is now considered invasive. Motherwort could possibly be confused with field mint (Mentha arvensis) but field mint lacks the distinctive three- or five-lobed angular-cleft leaves of motherwort and has boldly-protruding stamens that are lacking in motherwort.

Leonurus

Leonurus cardiaca

motherwort [Blooms: Jun-Aug]

Violet bush-clover produces racemes or sparsely branched panicles of 3-8 flowers from the tips of stems or axils of middle or upper leaves; the inflorescences are borne on long peduncles that extend above/beyond the leaves. Individual flowers are 6-10 mm long and pea-like; they include a light green calyx with five teeth that is half the length of the flower; five whitish purple to purple petals (one upright banner with a basal patch of rosy purple; two lower, outer wings shorter than the keel; and two lower, inner petals that make up the keel); 10 stamens; and a pistil with a single style. Both the stamens and style are usually hidden within the keel. Fertilized flowers produce small green, single-seeded seedpods that lack sticky hairs (unlike the much-larger tick-trefoils); at maturity, the seedpods are 4-7 mm long and dark brown.

Lespedeza

Lespedeza frutescens

violet bush-clover [Blooms: Aug-Sep]